Effects of γ irradiation on bis(2-ethylhexyl)phosphoric acid supported by macroporous silica-based polymeric resins

摘要

Bis(2-ethylhexyl)phosphoric acid (HDEHP) is one of the most intensively used extractants in solvent extraction, and its particular interest lies in the its application in nuclear fuel cycle as an extractant supported by macroporous silica-based polymeric resins in solid phase extraction technique. In this study, HDEHP/SiO2-P was synthesized by impregnation and immobilization, and we mainly focused on its radiation-resistant properties against γ-rays. It was found that HDEHP/SiO2-P still had good adsorption and separation properties after γ-irradiation by batch experiment. The uptake capacity of Gd(III) towards HDEHP/SiO2-P decreased slightly after irradiation. HDEHP/SiO2-P did not show any changes in the characterization of infrared spectroscopy and thermogravimetric analysis before and after irradiation. UPLC-Q-TOF-MS was employed to investigate the reaction mechanism in radiolysis of HDEHP in irradiated filter liquor. HDEHP/SiO2-P had a satisfactory radiation-resistance and chemical stability, even though it was exposed to the high absorbed dose of 500 kGy by γ-rays.